This invention relates to cladding systems in which cladding sheets are fastened to a supporting structure to cover the structure.
Cladding systems of this general type are already known in which the supporting structure is formed with clips arranged to clip the sheets in position. In general, the sheets overlap one another with a hook at one edge of one sheet engaging a formation, usually a rolled formation, at the adjacent edge of a similar, neighbouring sheet. The first-mentioned sheet has, on its edge opposite to the hooked edge, a formation for engagement by the hook of a neighbouring sheet on the opposite side.
In one known system, members of the supporting structure have clips in the form of cleats which are deformed over the formations of the sheets to hold them to the structure. For industrial applications, where one is dealing with large spans, the supporting structure is usually fabricated as a truss from steel members, and the cleats can be stamped from the steel of the members. Where the loading and correspondingly the spans, are less, timber members are preferred, and the cleats then have to be separate components which are fastened to the timber. The cleats have to be accurately positioned to mate correctly with the cladding sheets, which will usually have standard dimensions. The solution to the problem of accurate cleat spacing has been to fasten elongate rails to the timber members using spaced screws, the rails having the cleats stamped from them at the correct intervals. The problem nevertheless remains that the timber members are usually of fairly large cross-section so that they have sufficient structural strength to resist the imposed loads. A large amount of timber is required.
U.S. Pat. No. 3,236,932 (Grigas) describes a system in which vertical "furring strips" 24 are rivetted or nailed at intervals to upright members of timber. The furring strips have non-deformable cleats which are used to engage the cladding sheets. Because the "furring strips" are not fastened intimately and continuously to the upright member, they do not reinforce the member to any great degree i.e the "furring strips" serve only for the connection of the cladding.
In U.S. Pat. No. 3,347,009 (Meddick) nails 15 serve to secure a rail 12 to a member 13 at spaced intervals. The rail carries non-deformable formations 16, 17 for the connection of cladding sheets. Once again, the rail serves only to support the cladding sheets without providing reinforcement for the member 13.
In U.S. Pat. No. 4,047,349, a rail 18 has deformable cleats which are used to engage cladding sheets. The rail is fastened at spaced intervals to a vertical member 12, but again endows that member with no real added strength.
In the composite beams seen in U.S. Pat. No. 4,281, 497, there is a U-shaped flange which is connected to a member at spaced intervals by means of spaced tabs which bite into the material of the member. Further tabs, in conjunction with bolts or screws can be used to secure cladding sheets to the flange.
One object of the invention is to provide a support member for a cladding system in which support member there is a rail which is secured continuously and intimately to a timber member to reinforce it, and which has easily deformable cleats which allow for rapid connection of cladding sheets to the rail. Other objects of the invention include the provision of a cladding system employing such a support member.